This invention relates to a method of detecting a pathogen using a virus.
More specifically, the invention relates to the detection of the pathogen Brucella abortus using the virus Brucella bacteriophage.
Brucellosis is a disease caused by the bacterial genus, Brucella, named after Dr. David Bruce who discovered the organism in 1887. The disease is zoonotic, although different species are usually found in specific domestic animals, such as cattle (B. abortus), swine (B. suis), sheep (B. ovis), goats (B. melitensis) and dogs (B. canis). The manifestations of these bacteria in animals are usually reproductive complications (aborted fetuses, inflamed uterus or orchitis). While vaccinations in animals have proven partially effective in offering protection, the vaccines are pathogenic for other animals and humans. Infection is passed to humans through the ingestion of milk, milk products, the handling of contaminated carcases or aborted fetuses, and by the contact of infected tissues or body fluids. The disease is rarely passed from human to human, and then usually by exposure to contaminated blood specimens. Brucella is the number one cause of laboratory acquired infection. The great majority of patients with the disease survive, but only a small percentage ever recover completely. Usually the people infected are subject to relapses of recurrent, or undulant, fever, incapacitation, nausea and arthritis.
Brucella is a highly infective organism which causes debilitating symptoms, and which can persist in the environment for months under the right conditions. There are no effective vaccines and only limited therapeutic recourses to the bacteria. In other words, Brucella is potentially a bacterial warfare agent. Accordingly, there is a need for an effective detection assay.
Methods are available for the detection of pathogenic bacteria, but these have limitations. Culturing bacteria from clinical specimens is sensitive but often requires selective media, several days of incubation and the right nutrients or conditions (Brucella needs 5-10% carbon dioxide). Common serological techniques are usually insensitive. The enzyme-linked immunosorbent assay is usually rapid, sensitive and specific but gives false-positive for Staphylococcus aureus protein A, requires a source of antibodies which is difficult to raise, and may not detect different strains of the same species.
The object of the present invention is to meet the above defined need for an effective detection assay for Brucella (specifically Brucella abortus) in the form of an assay for the detection of pathogenic bacteria by using bacteriophages, a type of virus that is specific for host bacteria.
Accordingly, the present invention relates to a method of detecting the presence of a pathogenic bacteria in a liquid sample using a bacteriophage specific to the bacteria comprising the steps of producing a bacteriophage stock; conjugating the bacteriophage stock to an enzyme; mixing the conjugated bacteriophage with a sample suspected of containing the bacteria; and detecting any changes resulting from a reaction of the conjugated bacteriophage with the bacteria.
More specifically, the invention relates to a method of detecting the presence of the bacteria Brucella abortus in a sample using virus Brucella comprising the steps of producing a stock of Brucella bacteriophage, conjugating the Brucella bacteriophage to the enzyme urease; mixing the conjugated Brucella bacteriophage with a sample suspected of containing the bacteria Brucella abortus; and detecting any changes resulting from a reaction of the conjugated Brucella bacteriophage with the Brucella abortus.